When I had a project to render docx files, I had to refer the ECMA pdfs which were tens of thousands of pages long and use that only to supplement reverse engin

When I had a project to render docx files, I had to refer the ECMA pdfs which were tens of thousands of pages long and use that only to supplement reverse engineering Word documents. I also remember something hardly decclarative: if a picture was angled, I had to calculate the container boundaries and store it redundantly in the container.